Rubidium is widely distributed throughout the terrestrial crust. It is a relatively abundant element when compared to lead, copper, zinc or cesium. No minerals have rubidium as the main constituent. However, some potassium ores contain compounds of the element, such as the Rb2O, present in the lepidolite, amazonite, leucite, pollucite, petallite, beryl or biotite. In the carnallite it is possible to find 0,035% rubidium chloride. One can also find rubidium in common rocks as granite, basalt and several clays, or still in ocean and natural spring waters. Due to its widely distribution, the extraction is very complex and expensive.